Reverting driver.makefile to nfs version (propopsed rc3.1.4)

We need to combine the changes we have made in the conda require (allowing non-pinned versions) while undoing the changes to driver.makefile that were conda-specific. There is likely a lot more work to be done in this, but that belongs in a separate project and will be looked at later.

This is necessary before we can go and build the necessary modules for EPICS base 7.0.4 to test properly.